Literary Notices. v 



of exposure of the small white target. The pendulum myograph used 

 for this purpose also registers the amount of error. No evident rela- 

 tion exists between the time employed and the accuracy displayed, 

 but the time interval of females is longer while their motions are more 

 accurate. It would appear that some such a system of tests might be 

 employed in the study of the effects of various crafts. 



The Motor Power of Ideas.^ 



The curious observation has been made that if one gazes fixedly 

 at a light for twenty seconds or so, and then suddenly turns the head 

 through an angle of 45 degrees, he has an after image in the direction 

 toward which the head is turned ; while on the other hand, if the light 

 is viewed but one second, the after image appears in the direction of 

 the actual flame. 



Miinsterberg found that the eyes were unconsciously turned 

 toward the direction where the flame was seen before the change in 

 the second case while in the former they passively follow the motion 

 of the head. The explanation given is as follows: "When I open 

 my eyes and see a flame, this optical impression brings out the motor 

 effect of fixing my eyes upon it — an effect which is the essential ele- 

 ment in attention. When I turn my head with closed eyes this head 

 movement acts as a stimulus to a motor reaction of the eyes. This 

 second stimulus is, of course, the same whether I turn my head after 

 twenty seconds or after one second. Now if this same stimulus brings 

 out two so very different effects, it must be because the stimulus from 

 the optical impression is different after twenty seconds and after one 

 second. After one second the optical stimulus is stronger than the 

 head-stimulus, and the eyes turn therefore toward the flame." 



The experiments reported were made with a view to determine 

 how the motor impulse to fixate the eyes upon an object varies with 

 the quality of the impression and with the time of fixation. A black 

 frame with an opening to receive the test objects was placed directly 

 in front of the subject and 60 cm. distant. At a signal given by the 

 kymograph the eyes are opened and fixed on the object. After an 

 interval another signal is given at which the eyes are closed and the 

 head is turned through 45 degrees as nearly as possible and the eyes 

 are opened. Note is then made on a suitably arranged arc of the po- 

 sition of the head and the angular divergence of the eyes. It was, 



iMUENSTERBERG and CAMPBELL. Psycholog. Rev, I, 5. 



