"On entering the library, which was illuminated by a single lamp, I found myself alone. I drew a chair to the fire, and, taking up a volume of M. Renan's which chanced to be lying on the table, I composed myself to detect the sophistries of this brilliant but unprincipled writer. Thus, by an effort of will, I distracted myself from that state of 'expectant attention' to which modern science attributes such phantoms and spectral appearances as can neither be explained away by a morbid condition of the liver, nor as caused by the common rat (Mus rattus). I should observe by the way," said the learned bishop, interrupting his own narrative, "that scepticism will in vain attempt to account, by the latter cause, namely rats, for the spectres, Lemures, simulacra, and haunted houses of the ancient Greeks and Romans. With these supernatural phenomena, as they prevailed in Athens and Rome, we are well acquainted, not only from the Mostellaria of Plautus, but from the numerous ghost-stories of Pliny, Plutarch, the Philopseudes of Lucian, and similar sources. But it will at once be perceived, and admitted even by candid men of science, that these spiritual phenomena of the classical period cannot plausibly, nor even possibly, be attributed to the agency of rats, when we recall the fact that the rat was an animal unknown to the ancients. As the learned M. Selys Longch observes in his Etudes de Micromammalogie (Paris, 1839, p. 59), 'the origin of the rat is obscure, the one thing certain is that the vermin was unknown to the ancients, and that it arrived in Europe, introduced, perhaps, by the Crusaders, after the Middle Ages.' I think," added the prelate, looking round, not without satisfaction, "that I have completely disposed of the rat hypothesis, as far, at least, as the ghosts of classical tradition are concerned." "Your reasoning, bishop," replied Lord Birkenhead, "is worthy of your reputation; but pray pardon the curiosity which entreats you to return from the simulacra of the past to the ghost of the present." "I had not long been occupied with M. Renan," said the bishop, thus adjured, "when I became aware of the presence of another person in the room. I think my eyes had strayed from the volume, as I turned a page, to the table, on which I perceived the brown strong hand of a young man. Looking up, I beheld my friend the priest, who was indeed a man of some twenty-seven years of age, with a frank and open, though somewhat careworn, aspect. I at once rose, and asked if I could be of service to him in anything, and I trust I did not betray any wounding suspicion that he was other than a man of flesh and blood.