ILLUSIONS OF THE SENSES 151 



on the table or in the palm of the left hand. Then cross 

 the fingers of the right hand as shown in the engraving, 

 Fig. 22, the second finger crossing the first, and place them 

 on the ball, so that the latter may lie between the fingers, 



Fig. 22. 



as figured in the cut. If the pea or ball be now rolled 

 about, the sensation is apparently that given by two peas 

 under the fingers, and this illusion is so strong that it can- 

 not be dispelled by calling in any of the other senses (the 

 sense of sight for example) as is usually the case under 

 similar circumstances. We may try and try, but it will 



