LEGERDEMAIN, lej'er-de-man' (Fr., sleight of hand). The art of performing tricks of de ception—in the narrower sense. with the hands alone; broadly, with any aid of physical ap pliances.
The arts of magic. seemingly as ancient as human intelligence, are of two general types: (1) Forms such as necromancy. divination, sor cery or enchantment, perhaps astrology. in which the magician works by means of spells. incanta tions, or of some occult science supposed to give him knowledge of superhuman agencies and power to direct them; (2) legerdemain and jugglery in which the magician displays his own skill at wonder-working. Ordinarily, among primitive peoples, the magician—witch-doctor, medicine man, or what not—is himself deceived by the usages of magic of the first type. receiving them as mysteries of his cult and implicitly relying upon their efficacy. Magic of the second type, however, is used and understood by him merely as a means of impressing his more ignorant fellow-men with a sense of his power; it is con scious deception. This distinction is significant in the history of magic and is maintained even in modern civilization: for, although many forms of the first type of magic are imitated by tricks of legerdemain, notoriously in the spiritualistic seance, there still persists credulity in occultism in connection with the frankest recognition of the natural causes of the deceptions of jugglery.
Legerdemain and jugglery are sometimes grouped under the title 'natural magic,' probably on the analogy of 'natural philosophy,' since so many of their deceptions are applications of sim ple principles of physics and chemistry; but the two terms are not precisely synonymous. Jug glery is the broader term, denoting not only tricks of deception, but performances with para phernalia demanding great skill and dexterity, in which no deception is intended. Legerdemain, however, is confined simply to tricks of deception. The diverse development is perhaps illustrated in the jugglers of India and those of Japan. The performances of the former so often cited, such as the mango trick, the basket trick, and the snake charming trick, are properly legerdemain, de pending for their deception upon some type of substitution; whereas the feats of the Japanese are very largely feats of equilibration, as the balancing of objects upon various parts of the body, demanding great skill, but not as a rule designed to deceive.
In legerdemain proper the essential feature is generally an net of substitution, as when, for ex ample. the performer seems to discover eggs, money, and the like objects in places previously perceived to be empty. Often the substitution requires for its efficiency elaborate. mechanical devices, though the most skillful thaumaturgists prefer to rely upon their own manual dexterity. The power of deceiving is almost invariably due to power of diverting the percipient's attention at a crucial moment—the moment of the substi tution. In this even more than in celerity of movement lies the essence of the art. The
psychological principles underlying the deception rest wholly upon the laws of attention. In pro portion as attention is intensified. its scope be comes narrowed; as. for example, concentrated inspection of any object renders stimuli affecting the marginal regions of the field of vision prac tically invisible. It is, accordingly, the first duty of the performer to centre the percipient's at tention as strongly as possible upon the object matter of the trick to be performed. Succeed ing in this, he gains a practical control over the percipient's range of vision and has little diffi culty in diverting it at the crucial moment. It may thus be said that the keenest scrutiny is the likeliest to fall victim to the trick.
The part of the legerdemainist himself, how ever, is one of great difficulty: for he must he able to discoOrdinate his actions and diversify his attention to a degree only attainable by long practice. His hands and eyes must be trained to work apart—the hands performing the substitu tion. eyes and bodily pose misleading the per cipient. Similarly, his attention must compre hend and direct many diverse details at once.
The origin of thaumaturgy is of remote an tiquity. Savages the world over have developed cults and mysteries which transmit. with other lore. tricks of legerdemain from generation to generation. The Navaho Indians perform a trick with the cactus alini)st identical with the mango trick of India ; and nearly all of the simpler per formanecs are known to widely separated peo ples. The wonder-workers of Egypt and lesopo Iambi were aneientl• famous, and many 411 the miracles recorded indicate that the Roman priests utilized principles of hydrostatics and optics for the production of illusions. Jugglers were kmovn among the .Anglo-Saxons, lint appear to have attained no great proficiency. Indeed, it was only with Hobert Houdin (1805-71) that legerdi.main became a matter of science. Houdin built clever contrivances and wrote several books on the subject, Dever elaiming to he a wonder-worker in miraculous sense. but only a clever manipulator. Since his day callers—nota bly the Ilerrmanns—have advaneed the art to a degree far in advance of any previously attained. On the other hand, many impostors have utilized legerdemain to produce 'materializations' of spirits, elairvoyant readings, slate-writings, and the like. Hypnotism has also been widely used by professional exhibitors—often fraudulently; and very many tricks which are merely exhi bitions of known natural principles or feats of apparent strength, as the supporting of weights on the pelvic arch, have been passed as thauma turgie phenomena.
Consult: Pousin, Nouvelle magic blanehe roih'e (Paris, 1853-54) ; No•eellerie aneiennc rt MOder»C (1858) ; Hobert Houdin, Se crets (le la iwestidillitation et (lc la magic (Paris, 1St f8 : Brewster. Natant/ Magic London, 1851) ; Hopkins, Magic (New York, 1898).