206 THE ADDRESSES, LECTURES, ETC., OF 



one system upon the other being attributable to mental energy. 

 It may be conceived that any fresh impressions received on the 

 extremely complex sensitive network of the brain may give rise 

 then and there to acts of volition ; but how, it may be asked, can 

 acts of volition arise from impressions that were communicated 

 through the sensitive nerves years before, having been committed 

 in the meantime to what we term the memory ? But in order 

 that the mind can deal with an impression previously received it 

 seems necessary that it must have the power of reproducing the 

 same from some material record by which the impression has been 

 rendered permanent. Take the case of a tune that we have heard 

 in early youth and which may not have since recurred to us. By 

 some incident or other that tune and the words connected with it 

 become suddenly revivified in the mind. If the tune had been 

 sung into a phonograph it could have been reproduced at any 

 time by releasing a spring moving the barrel of the instrument ; 

 and it seems a fair question to ask whether the grey substance of 

 the brain may not, after all, be something analogous to a store- 

 house of phonographic impressions representing the accumulated 

 treasure of our knowledge and experience, to be called into 

 requisition by the directing power of the mind in turning on, as it 

 were, one barrel or another. 



Such a hypothesis might possibly serve also to explain how in 

 sleep, when the directing power of the mind is not active, a local 

 disturbance in the nervous system may turn on one or more 

 phonographic barrels at a time, and thus produce the confused 

 images of dreamland ! A powerful mind would exercise a 

 complete control over the innumerable barrels constituting our 

 store of knowledge, whereas in a weak mind the impressions of 

 the past would be brought back into evidence in a confused and 

 irregular manner. Such a supposition might also account for the 

 more vivid recollection of impressions received in early life, when 

 the mechanical record stored up in the brain may be supposed to 

 have been more distinctly and indelibly rendered. In speaking of 

 these impressions as phonographic it does not follow that they 

 were originally conveyed through the tympanum of the ear. 

 Mr. Willoughby Smith, at the meeting above referred to, called 

 attention to the fact that, by substituting crystalline selenium for 

 carbon in the microphone, a ray of sunlight directed upon the 



