_Catoptromancy_, or divination by the mirror, is as old as the time of the Roman Emperors. In one of the passages relating to this method of inducing what is called clairvoyance, we have an illustration of the early acquaintance of mankind with some of the forms of mesmerism. The passage is found in Spartian’s life of Ditius Julian, the rich Roman who purchased the Empire when it was put up to auction by the Prætorian guards. "Julian was also addicted to the madness of consulting magicians, through whom he hoped either to appease the indignation of the people, or to control the violence of the soldiery. For they immolated certain victims (human?) not agreeable to the course of Roman sacrifice; and they performed certain profane incantations; and those things, too, which are done at the mirror, in which boys with their eyes blindfolded are said, by means of incantations, to see objects with the top of the head, Julian had recourse to. And the boy is said to have seen (in the mirror) both the approach of Severus and the death of Julian." The passage may be variously rendered, according to different readings and punctuations, either as "boys, who can see with their eyes blindfolded, by reason of incantations made over the top of the head;" or, "boys, who, having their eyes blindfolded, can see with the top of the head, by reason of incantations;" or, "boys, who, having their eyes blindfolded, can see with the top of the head, it being operated on by way of incantation." This seeing, or seeming to see, with the top of the head, is one alleged variety of the modes of modern clairvoyance. It seems difficult to imagine that the boy Horner, whose case is related by Mr. Topham, in a letter to Dr. Elliotson, dated May 31, 1847, could have heard any thing of these pagan practices. Mr. Topham, a barrister and man of credit, states: "After five or six weeks’ mesmerism, he began spontaneously to exhibit instances of clairvoyance. The first occasion was on the 11th of September. It was in the dusk of the evening, so that the room where he was mesmerised was nearly dark. My previous mode of mesmerising him had been by pointing at his eyes, but on this occasion I began by making passes over the top of his head, and continued them after he was in the sleep. In the course of five or six minutes after the sleep was induced, he suddenly exclaimed that he could see into the room above us (the drawing-room). I said, ’Your eyes are closed; how can you see?’ And he replied, ’I don’t see with my eyes; I see from the top of my head. All the top of my head seems open.’ He then described, &c. I found every thing as he had described, &c." Mr. Topham, it need scarcely be added, does not appear to have been at all aware of the passage in Spartian, which, indeed, has not been cited or referred to in any published work for nearly two hundred years back.