On leaving the baths of San Giuliano, after the floods, the Shelleys returned to Pisa, where they passed the late autumn and winter of 1820 and the spring of 1821. Here they made more acquaintances than heretofore, Professor Pacchiani, called also "Il Diavolo," introducing them to the Prince Mavrocordato, the Princess Aigiropoli, the improvisatore Sgricci, Taafe, and last, not least, to Emilia Viviani. Here Mary continued to write Valperga, and pursued her Latin, Spanish, and Greek studies; the latter the Prince Mavrocordato assisted her with, as Mary writes to Mrs. Gisborne: "Do not you envy me my luck? that, having begun Greek, an amiable, young, agreeable, and learned Greek prince comes every morning to give me a lesson of an hour and a half."

But the person of most moment at this time was undoubtedly the Contessina Emilia Viviani, whom, accompanied by Pacchiani, Claire, then Mary, and then Shelley, visited at the Convent of Sant' Anna. This beautiful girl, with profuse black hair, Grecian profile, and dreamy eyes, placed in the convent till she should be married, to satisfy the jealousy of her stepmother, became naturally an object of extreme interest to the Shelleys. Many visits were paid, and Mary invited her to stay with them at Christmas. Shelley was convinced that she had great talent, if not genius. Shelley and Mary sent her books, and Claire gave her English lessons at her convent, while she was taking a holiday from the Bojtis. Many letters are preserved from the beautiful Emilia to Shelley and Mary, letters which, translated into English, seem overflowing with sentiment and affection, but which to Italians would indicate rather the style cultivated by Italian ladies, which, to this day, seems one of their chief accomplishments if they are not gifted with a voice to sing. To Mary she complains of a certain coldness, but certainly this could not be brought to the charge of Shelley, who was now inspired to write his Epipsychidion. To him Emilia was as the Skylark, an emanation of the beautiful; but to Mary for a time, during Shelley's transitory adoration, the event evidently became painful, with all her philosophy and belief in her husband. She could not regard the lovely girl who took walks with him as the skylark that soared over their heads; and the Epipsychidion was evidently not a favourite poem of Mary. Surely we may ascribe to this time, in the spring of 1821, the poem written by Shelley to Lieutenant Williams, whose acquaintance he had made in January. There is no month affixed to—

The Serpent is cast out from Paradise….

and it might well apply, with its reference to "my cold home," to the time when Mary, in depression and pique, did not always give her likewise sensitive husband all the welcome he was accustomed to, and Shelley took refuge in a poem by way of letter; for this is the time referred to by Mary in her letter to Claire as their seventh unfortunate spring—a mixture of Emilia and a Chancery suit! It was not till the next spring that Emilia was married, and led her husband and mother-in-law, as Mary puts it, "a devil of a life." We have only to be grateful to Emilia for having inspired one of the most wondrous poems in any language.

The Williamses, to whom Shelley's poem is addressed, were met by them in January. Mary writes of the fascinating Jane (Mrs. Williams) that she is certainly very pretty, but wants animation; while Shelley writes that she is extremely pretty and gentle, but apparently not very clever; that he liked her much, but had only seen her for an hour.

Mary, among her multifarious reading, notes an article by Medwin on Animal Magnetism, and Shelley, who suffered severely at this time, shortly afterwards tried its effect through Medwin. The latter bored Mary excessively; possibly she found the magnetising a wearisome operation, although Shelley is said to have been relieved by it. His highly nervous temperament was evidently impressed. When Medwin left, Mrs. Williams undertook to carry on the cure.

The Chancery suit referred to by Mary was an attempt between Sir Timothy's attorney and Shelley's to throw their affairs into Chancery, causing great alarm to them in Italy, till Horace Smith came to their rescue in England, and with indignant letters settled the inconsiderate litigation.

Mrs. Shelley, in her Notes to Poems in 1821, recounts how Shelley was nearly drowned, by a flat boat which he had recently acquired being overturned in the canal near Pisa, when returning from Leghorn. Williams upset the boat by standing up and holding the mast. Henry Reveley, Mrs. Gisborne's son, rescued Shelley and brought him to land, where he fainted with the cold. At this same time, at Pisa, Mary had to consider with Shelley a matter of great importance to Claire.

Byron, now at Ravenna, had placed Allegra, as already stated, in the convent of Bagnacavallo. He told Mrs. Hoppner that she had become so unmanageable by servants that it was necessary to have her under better care than he could secure, and he considered that it would be preferable to bring her up as a Roman Catholic with an Italian education, as in that way, with a fortune of five or six thousand pounds, she would marry an Italian and be provided for, whereas she would always hold an anomalous position in England. At this proposal Claire was extremely indignant; but Shelley and Mary took the opposite view, and considered that Byron acted for the best, as the convent was in a healthy position, and the nuns would be kind to the child. This idea of Mary would naturally be agreed with by some, and disapproved of by others; but at that time there was certainly no cause to indicate that Bagnacavallo would be more fatal to Allegra than any other place, although Claire's apprehensions were cruelly realised. From this time Claire and Byron wrote letters of recrimination to each other, which, considering Byron's obduracy against the feelings of the mother, Shelley and Mary came to hold as tyrannically unfeeling.

In May, Shelley and his wife and son returned to the baths of San Giuliano, and while here Shelley's Adonais was published. In 1820, when the Shelleys heard of Keats's fatal illness from Mrs. Gisborne, she having met him the day after he had received his death warrant from the doctor, they were the first to beg him to join them at Pisa. A small touch of poetical criticism, however, appears to have weighed more with the sensitive Keats than these friendly considerations for his health, and as he was about to accompany his friend Mr. Severn to Rome, he did not accept their kind offer, though in all probability Pisa would have been better for him.