3J7 



that has been blackened on the back-side, have been attached, are 

 pushed into this opening. In front of the box tfiei'e is another hinip, 

 whicli is lighted during one second antomaticaily. As this light falls 

 on the drawings they are exposed to the subject during one second. 

 The snbject has been told to remember the ordei- of the drawings. 

 The number of exposures necessary before he can do this is a 

 measure foi- tiie facultj' of inculcation. 



Then the same test is again put, but with the drawings in a 

 different order and with this modification that the lamp in the box 

 is turned on immediately after the exposure of the drawings, so 

 that the full light out of the box falls on the eyes of the subject 

 during sexeral seconds after observation of the drawings. By 

 determining how often nnder these circumstances the observation 

 had to take place for the subject to be able to name the correct 

 order, oi^e could now determine the retrograde annihilating influence 

 of the strong light. 



Persons of various ages were examined by this method. The 

 number of observations, the average of two tests, necessary to 

 determine the order of the drawings, without and with the subsequent 

 strong light, is expressed in the following table: 



Age 



Number Without obstacle 



2.3 

 2.4 

 2.6 



With sub- 

 sequent light 



4.2 

 4.3 

 5.2 



The children have thus to see the drawings 2.3 times. In each 

 observation they then lemember ^t or 43.5 7o ^"d with a subsequent 

 strong impulse |^f or 23.8 "/o- When expressed in percentages we 

 get the following table : 



Proc.ccdiri'rs Royal Acad Amstn dain. Vol NXi. 



21 



