Memory. 673 



At the moment of the waking of some of the cells, others are still 

 in the insensibility of sleep. Those first stimulated and erected may lie 

 along a continuous and coherent track of memory, arousing the whole 

 line, and giving a sensation of a complete memory, which, mingling 

 with other such lines, produce an image more or less complete. But in 

 most lines of memor}^, some of the details are faint, while others are 

 deep-set. If two persons undertake to relate the same incident, one 

 will reproduce details not remembered, or remembered faintly, by the 

 other. So, in the re-erections of cells at the moment of waking, we can 

 readily conceive that before the action of the stimulus has reached its 

 maximum, these faintly impressed cells may be passed by without being 

 aroused, the result being a confused lot of incomplete images jumbled 

 together without order or coherence. 



In the semi-conscious state in which dreams take place, those cells on 

 which depend the standards of rational deductions and the moral senti- 

 ments, are usually still inactive and asleep. It is on this account that 

 neither the intellectual faculties are surprised, nor the moral sensibili- 

 ties shocked, by our dreams, as they would be often by such images if 

 presented in waking hours. The cells in question belong to a class 

 whose excitation has not been, in the first place, directly from the en- 

 vironment, but at second or third hand from the cells of sensory im- 

 pression. It is their re-erection in sleep that constitutes what is called 

 unconscious cerebration. The only distinction between that and dream- 

 ing, consists in the class of cells restimulated, and the completeness and 

 coherence of the recollection. 



Injury to the cerebrum deranges or destroys the memory, affecting it 

 in many different ways. Sometimes epilepsy or apoplexy destroys the 

 power of the reception of new impressions, so that the patient does not 

 remember anything that passes from day to day, whilst very old impres- 

 sions come up vividly. At other times, the old events are blotted out, 

 and the late ones are vivid. 



We are accustomed to talk loosely about the revival of a remembrance 

 through the will. Using the term as commonly applied, we yet find the 

 process is not by any means a direct and simple one. We do not call 

 up any idea by simply willing it, for this presupposes that we have an 

 idea of the idea we wish to recall, which if we had, no further recollec- 

 tion would be necessary. What is really done in recollecting is the fix- 

 ing of attention upon such outlying contiguous and associated or con- 

 stituent elements of the idea we want as are present in the memory, so 

 that the activities of these will overflow along the lines of association 

 by which they were connected in the first place with the ones now 

 wanted, and so re-erect them, or reproduce them by suggestion. Thus, 

 in trying to remember a quotation, as, for example, a verse of poetry, 



