ON MEMORY 191 



tent, similar to that felt on the evening when he 

 witnessed the scene, again comes over him. This 

 we call memory — our recollection or remembrance 

 of those experiences. 



Whence and how, apparently disconnected from 

 the causes which produced the primary impressions, 

 do these manifestations arise again in the mind? 

 To find an answer to this question, consideration 

 must first be given to the problem of how the 

 real causes produced the primary impressions. 



The sound waves from the vibrations of the bells 

 affected the auditory nerves. The vibrations of 

 light transferred by meadow, hill, sky, landscape, 

 to the invisible ether were by this transmitted to the 

 nerves of sight. The infmitesimally small particles 

 of odorous matter exhaled by flowers, etc., into the 

 atmosphere affected the olfactory nerves. The 

 motions of the breeze reacted upon the nerves of 

 touch located under the skin of the face, neck, and 

 hands, and all these reactions affecting the nervous 

 system as a whole caused the general feeling of well- 

 being and content. It is obvious, then, that origi- 

 nal experiences were produced by external causes 

 acting on nerves. 



But this does not explain how the subsequent 

 fainter repetitions arose in the mind of the speaker, 

 after the external causes had for many days ceased 

 to act on his nerves. This mystery cannot be 

 explained except by one hypothesis : that when the 

 external causes were producing the original experi- 



