320 The Mnemonic Phenomenon 
faculty possessed by all living substance, it is in them 
that we shall be able best to verify the laws which be- 
come impressed upon this mnemonic faculty through the 
conception that it is based upon the specific accumula- 
tion and reproduction suggested above. And the most 
important of these laws have just been briefly outlined 
in the preceding chapters. 
Of the three elements of memory: the preservation 
of certain states, their reproduction, and their localization 
in the past, Ribot thinks that the first two alone are 
necessary and characteristic.23? We can note, that the 
hypothesis of mnemonic elements permits us to conceive 
of this preservation of certain states as an accumulation 
of specific energy and their reproduction as the discharge 
of that specific energy. 
“When we speak,” writes Maudsley, “of a trace, or 
vestige or residuum all we mean to imply is that an 
effect is left behind in the organic element, a something 
retained by it which disposes it to a similar functional 
act; a disposition has been acquired which differentiates 
it henceforth, although we have no reason to think that 
there was any original specific difference between one 
nerve cell and another.” ?%* This something which 
leaves an impression after it in the nerve cell and which 
disposes it to other similar functional acts will be to our 
mind, a true and real material residue of substance 
capable of reproducing the same functional current as 
that by which it had been deposited. And the differ- 
entiation of nerve cells, as indeed of all other somatic 
cells, consists in the acquisition by each of them of a 
*8Ribot: Ibid. P. 2. 
**4Maudsley: The Physiology of Mind. Third edition. Len- 
don, Macmillan, 1876. P. 270. 
