Experiments on Thought, d09 



H6mer, or any other lines that may be still more familiar tc^ 

 me, I cannot get through them much, if at all, more rapidly 

 than I can pronounce them, even when I fix my undivided 

 attention on them. 



The rapidity of sensation is also intimately connected with 

 that of memory and of muscular action. To cast the eye over 

 a sentence, attending to every letter, is an operation which is 

 capable of equal rapidity with the saying it over mentally : but 

 it cannot be made much more rapid. It required four seconds 

 to look over a sentence which occupied six in rapid reading. 



The operations, which succeed each other with this limited 

 rapidity, are not incompatible with a partial attention to other 

 subjects i just as in running or walking, we may have our 

 feelings very strongly interested by the sight of surrounding 

 objects without interrupting the train of voluntary motions, 

 which seems thus to be so linked together in a continued 

 chain, as to become almost involuntary. And we may cer- 

 tainly be saying a thing over as rapidly as possible to our- 

 selves, and may at the same time be seeing, and hearing, and 

 even reasoning, so as to keep up what amounts very nearly, 

 though not completely, to a continuity of attention to several 

 distinct trains of ideas : in the same manner as the nerves 

 of involuntary action are notoriously employed in several dis- 

 tinct trains of concatenated muscular motions and vascular 

 actions, and as the ear of a musician is able to follow and 

 retain a dozen different melodies in harmony with each other 

 at the same time. 



Dr. Danvin mentions an experiment which has a similar 

 tendency to show the close connexion between thought and 

 sensation. He says, that if we think intensely of a deep 

 colour, for instance red, with the eyes closed, we shall see a 

 tinge when we open them of the opposite colour, or green ; 

 just as if we had actually looked at a red colour instead of 

 thinking of it. But I confess that I have never been able to 

 satisfy myself completely of the success of the experiment. 



These very hasty observations appear to me to be in great 

 measure original ; and the results of such experiments are 

 certainly more calculated to illustrate the nature and powers 

 of the human mind, than the fanciful hypothesis of the fashion- 



