We believe that the spread of modern magic and its proper comprehension are an important sign of progress, and in this {xix} sense the feats of our Kellars and Herrmanns are a work of religious significance. They are instrumental in dispelling the fogs of superstition by exhibiting to the public the astonishing but natural miracles of the art of legerdemain; and while they amuse and entertain they fortify the people in their conviction of the reliability of science. [Illustration: ZÖLLNER’S ILLUSION] In speaking of modern magic, we refer to the art of the prestidigitateur, and exclude from its domain the experiments of hypnotism as well as the vulgar lies of fraud. There is no magic in the psychosis of an hysterical subject, who at the hypnotizer’s suggestion becomes the prey of hallucinations; nor is there any art in the deceptions of the fortune-teller, whose business will vanish when the public ceases to be credulous and superstitious. The former is a disease, the latter mostly fraud. Magic proper (i. e., the artifices of prestidigitation) is produced by a combination of three factors: (1) legerdemain proper, or sleight of hand; (2) psychological illusions, and (3) surprising feats of natural science with clever concealment of their true causes. The success of almost every trick depends upon the introduction of these three factors. The throwing of cards is mere dexterity; Zöllner’s famous figures of parallel lines having an apparent inclination toward {xx} one another is a pure sense-illusion (see cut here reproduced); so is the magical swing; while fire-eating (or better, fire-breathing) is a purely physical experiment. But it goes without saying that there is scarcely any performance of genuine prestidigitation which is not a combination of all three elements. The production of a bowl of water with living fishes in it is a combination of dexterity with psychology. The trick with the glass dial (which is now exhibited by both Mr. Kellar and Mr. Herrmann, the nephew of the late Alexander Herrmann) is purely physical. The machinery used by them is entirely different, but in either case no sleight of hand nor any psychological diversion is needed, except in letting the accomplice behind the stage know the number to which he should point. As an instance of a wonderful trick which is a mere sense-illusion we mention the magic swing, which is explained by Albert A. Hopkins in his comprehensive book on magic[1] as follows: