570 PSYCHOLOGY OF PRESTIDIGITATION. 



other liaud, it is impossible for the spectator to see the trick, as the 

 hand remains constantly closed. 



The magic wand is of great service in tricks of this kind, as the very 

 fact that the wand is in the hand is reason enough for the hand 

 remaining partly closed, and therefore making it jwssible to conceal 

 many objects in its palm. Moreover, the prestidigitator does not hold 

 the wand in his hand all the time; when it becomes necessary for 

 him to use both his hands in presenting an object to the view of the 

 spectators, he lays his magic stick on the table; a moment afterwards 

 he takes it up and raps with it as a signal that the illusion is about to 

 take place. These movements appear to have so little significance 

 that the spectators have not only neglected to look at them but they 

 don't really perceive them. IsTevertheless, they are decidedly impor- 

 tant. In placing the wand on the table the prestidigitator relieves 

 himself of the embarrassing object; taking up the wand, he possesses 

 himself of another object. The lookers-on have seen nothing and sus- 

 pect nothing. 



IV. 



The preceding analysis demonstrates how very difficult it is, even for 

 an intelligent observer, to see everything that takes place in front of 

 him. To see everything it is not oidy necessary to open the eyes wide, 

 for the human eye is not like the photographer's ])late, which reflects 

 without discernment all the details of the reality. The mental percep- 

 tion of objects is subjected to intlueuces which cause certain objects 

 to be seen correctly, others not to be perceived, and still others 

 which do not exist are so vividly imagined that we believe we see 

 them. To complete our study we thought it would prove interesting 

 to have recourse to photography, which to-day is the natural, almost 

 indisi^ensable, accomi^animent of visual observation. Thanks to the 

 cooperation of Mr. Georges Uemeny, Professor Marey's clever assist- 

 ant, we have not been compelled to content ourselves with one or two 

 isolated examples. Mr. Demeny, with the aid of the new chronopho- 

 tographic apparatus willingly photographed several tricks of presti- 

 digitation. This apparatus, of which a description was given at the 

 Academy of Sciences, is capable of taking as many as thirty instan- 

 taneous photographs of one movement; each one of these photographs 

 is separated from the other by an equal space. The series of the 

 experiment gives at the same time the form of tlie phenomenon and 

 the length of time it occupies. It is well known that chronophotog- 

 raphy has found numerous applications in the domains of jihysical 

 and natural sciences. It is to photography we owe the analyzing of 

 many complex movements which, on account of their rapidity, escaped 

 the analysis of the eye, for instance, the flying of a bird, the difter- 

 ent gaits of the horse, the step of man while running or walking, and 

 in general, all physical exercises. 



