In the Autobiography of William Lilly, the famous astrologer, in the time of the Stuarts, a curious account is given of Alexander Hart, an astrologer, living in Houndsditch, about the year 1632. It seems, that Hart had entered into a contract with a countryman, who had paid him twenty or thirty pounds, to arrange a meeting between this countryman and a particular spirit, at an appointed time. But, either Hart's powers of raising the dead were unequal to the task, or the spirit had no inclination to keep up the countryman's acquaintance; certain it is, the spirit was unpunctual; and, the patience of the countryman becoming exhausted, he caused the astrologer to be indicted, for a cheat. He was convicted, and about to be set in the pillory, when John Taylor, the water poet, persuaded Chief Justice Richardson to bail him, and Hart was fairly spirited away. He then fled into Holland, where, a few years after, he gave up the spirit, in reality. Its unintelligible quality is the very essence of delusion. Nothing can be more unreasonable, therefore, than to mistake our inability to explain a mystery, for conclusive evidence of its reality and truth. That it is unintelligible or inexplicable surely affords less evidence of its reality, and truth, than is furnished of its falsehood, by its manifest inconsistency with all known natural laws. Bruce informs us, that the inhabitants of the western coasts of Africa pretend to hold a direct communication with the devil; and the evidence of the thing they assert is so very curious and imposing, that he and other travellers are entirely at fault, in their attempts to explain the mystery. Yet no one, for a moment, supposes, that Bruce had the slightest confidence in these absurdities. And yet, so great, so profound, was the belief of Friar Bacon, in this preposterous delusion, that, in his Opus Majus, page 65, he exclaims--"Oh, how happy had it been for the church of God, and how many mischiefs would it have prevented, if the aspects and qualities of the Heavenly bodies had been predicted, by learned men, and known to the princes and prelates of those times! There would not then have been so great a slaughter of Christians, nor would so many miserable souls have been sent to hell." This eminently learned man, Roger Bacon, refers, in this remarkable passage, to the various calamities, which existed, in England, Spain, and Italy, during the year 1264. The word, mathematician, seems to have been applied, in that age, exclusively to astrologers. Peter de Blois, one of the most learned writers of his time, who died A. D. 1200, says, in the folio edition of his works, by Gussanville, page 596--"Mathematicians are those, who, from the position of the stars, the aspect of the firmament, and the motion of the planets, discover things, that are to come."