PEECEPTION. 137 



much as possible in a given time, the rapid readers (as shown 

 by their written notes) usually give a better account of the 

 portions of the paragraph which has been compassed by the 

 slow readers than the latter are able to give ; and the most 

 rapid reader whom I have found is also the best at assimi- 

 lating. I should further say that there is no relationship 

 between rapidity of perception as thus tested and intellectual 

 activity as tested by the general results of intellectual work ; 

 for I have tried the experiment with several highly dis- 

 tinguished men in science and literature, most of whom I 

 found to be slow readers. Lastly, it is worth observing that 

 every one who tries this experiment finds that it is impossi- 

 ble, with any amount of effort at recollection, to remember, 

 immediately after reading the paragraph, all the ideas which 

 have been communicated to the mind by the paragraph. But 

 as soon as the paragraph is read a second time, the forgotten 

 ideas are instantly recognized as having been present to the 

 mind while reading. This sliows that tlie memory of a full 

 perception may, as it were, be immediately crowded out by 

 rapidly succeeding perceptions, to the extent of being 

 rendered latent, although it may be instantly recalled by the 

 recurrence of the same perception. 



So much, then, to show that the personal equation in 

 different individuals varies the more the greater the number 

 and the higher the intricacy of the perceptions which are to 

 be made in a given time. I must now say a few words to 

 show that the personal equation in the same individual 

 admits of being greatly reduced by practice in making par- 

 ticular perceptions. This is well known to astronomers so 

 far as simple acts of perception are concerned, and in all the 

 researches above mentioned touching the time-measurements 

 of simple perceptions, the experimenters found that practice 

 had the effect of reducino- the reaction-time. The deo'ree of 

 reduction which might thus be produced was itself made the 

 subject of experiment by Exner, who chose tlie old man 

 already mentioned in one of tlie above quoted tables as having 

 the unusually long reaction-time of 0-99o2''. After a little 

 more than six months' practice at the rapid signalling of an 

 electric shock, the old man's reaction-time was reduced to 

 0-1866'^ 



This universal fact of repetition serving greatly to reduce 

 the physiological time required for the performance of phy- 



