ARTIFICIAL SOMNAMBULISM. 183 



described are effective in producing the hypnotic condition, 

 or whether all are essential to success in the experiment. 



In the first place, the fastening of the feet may be dis- 

 pensed with. But it has its influence, and makes the 

 experiment easier. An explanation, or rather an illustration, 

 of its effect is afforded by a singular and interesting experi- 

 ment devised by Lewissohn of Berlin : If a frog is placed 

 on its back, it immediately, when the hand which had held 

 it is removed, turns over and escapes. But if the two fore- 

 legs are tied with a string, the frog, when placed on its back, 

 breathes heavily but is otherwise quite motionless, and does 

 not make the least attempt to escape, even when the experi- 

 menter tries to move it. ' It is as though/ say Czermak, de- 

 scribing the experiment as performed by himself, * its small 

 amount of reasoning power had been charmed away, or else 

 that it slept with open eyes. Now I press upon the cutaneous 

 nerves of the frog, while I loosen and remove the threads on 

 the fore-legs. Still the animal remains motionless upon its 

 back, in consequence of some remaining after-effect ; at last, 

 however, it returns to itself, turns over, and quickly escapes.' 



Thus far the idea suggested is that the animal is so 

 affected by the cutaneous pressure as to suppose itself tied 

 and therefore unable to move. In other words, this experi- 

 ment suggests that imagination acts on animals as on men, 

 only in a different degree. I may cite here a curious case 

 which I once noticed and have never been able to under- 

 stand, though it seems to suggest the influence of imagina- 

 tion on an animal one would hardly suspect of being at all 

 under the influence of any but purely physical influences. 

 Hearing a noise as of a cat leaping down from a pantry 

 window which looked out on an enclosed yard, I went 

 directly into the yard, and there saw a strange cat running 

 off with a fish she had stolen. She was at the moment 

 leaping on to a bin, from the top of which, by another very 

 easy leap, she could get on to the wall enclosing the yard, 

 and so escape. With the idea rather of frightening her 

 than of hurting her (does one missile out of a hundred flung 



