608 Mr. Charles Mercier [May 3, 



activity takes is determined by the structural arraugement that has 

 been impressed upon it. A loom may be set to produce a pattern of 

 fern leaves, or roses, or zigzags, or Grecian keys, or what not ; and 

 whatever pattern it produces is determined by the structural memory 

 that has been impressed upon it. According as the type has been 

 arranged, so is the character of the print that is produced. And simi- 

 larly, the cylinder of a phonograph may have impressed upon it the 

 structural memory of a sonata, or a comic song, or a business letter, 

 or a political oration ; and when it is set in motion, the output, the 

 mode of action, or what I have termed the active memory, faithfully 

 reflects the structural memory. In all these cases the mechanism 

 may remain for an indefinite time disposed in a structural arrange- 

 ment, retaining a structural memory, but inactive. But when the 

 loom or the lathe is connected with the engine ; when the phono- 

 graph is connected with the battery ; then the mechanism starts into 

 activity, and then the form which its activity takes is determined by 

 the structural memory. And similarly, the structural memory may 

 remain for an indefinite time in the nervous system, latent and inert; 

 but the moment the mechanism becomes active, its activity assumes a 

 form which is determined by the structure, and thus the structural 

 memory asserts itself. 



Although the inanimate and the living mechanisms are precisely 

 alike in the respects that have been c n usidered, there is another 

 respect in which they are profoundly different. Every exercise of 

 activity in the inanimate mechanism impairs the structural memory. 

 The bearings and screws of the lathe wear away, and the quality of 

 the work deteriorates. The running parts of the loom wear out, and 

 the quality of the cloth deteriorates. The face of the type is worn, 

 and the print suffers. The gutter in the wax of the phonograph 

 becomes smoothed by the friction of the style, and the definition of 

 the sounds is spoilt. But with the nervous mechanism, owing to the 

 opposite quality of the dynamic memory, activity has the opposite 

 effect. Every exercise of activity on the part of the nervous 

 mechanism consolidates and improves the structural memory, and 

 renders its future activity more facile, more certain and more accurate. 



Active memory in some parts of the nervous system, that is to 

 6ay in those that are newly formed or in course of formation, is 

 attended by Conscious Memory. So long as a new structural memory 

 exists, but remains the seat of no active process, so long conscious 

 memory remains possible, but not actual. Only when active process 

 takes place in the altered structure does conscious memory arise. If 

 by violence or by disease the structural memory is destroyed, the 

 corresponding conscious memory is for ever lost. When we speak 

 of a man with a well-stored mind, we mean that he has a large 

 number of structural memories in the higher regions of his nervous 

 system. The memories are not in his mind until the structure be- 

 comes active, and then the conscious memory arises. 



So far there is a parallelism between conscious memory and the 



