MEMORY. 619 
cause a permanent change in a cell. We all have experienced^^sudden impres- 
sions which we have never forgotten, and never have felt but once. 
To remember is to recur almost instantly without exertion of will, to recol- 
lect is to recall by associations, to gather ideas step by step until the impression 
sought is brought to mind. We recollect by association, by a group of cells 
vibrating which excites another and so on. According to Bain there'^are about 
one billion cells and five billion fibres. These fibres connect cells and conse^ 
quently groups. It will be readily understood how this occurs, if we bear in 
mind how we think ; how one thought brings another into consciousness. We 
smell a rose, its odor excites certain cells ; through fibre connections other groups 
are excited to vibration, and we are conscious of events where^,the rose assumed 
a prominent part. We see a face which recalls the name and peculiarities of the 
possessor. We see a house and recollect the persons living therein. The house 
causes an impression which excites to vibration a group of cells, which in turn 
brings other groups into activity and we know the occupants. Most of our 
thought is through association, comparatively little that is instantaneous. 
In remembering, time and space are of little value, but they are essential to 
recollection. When we indulge in retrospection, memory carries us back weeks, 
months and years. We cannot recollect without time and space. The time is 
the present, space the period between the occurrence and the present moment. 
We have a conscious and organized memory. When we perform an act 
with a distinct end in view it is the result of conscious memory. When a begin- 
ner is learning to play upon a piano, every note is struck by the effort of the will 
and therefore conscious. In setting our watch, we do it consciously, we have 
found the correct time and our mind is on the act, and we turn the hands care- 
fully until our aim is accomplished. Therefore every act of will power is the 
result of conscious memory. 
Intensity and duration are indispensable to conscious memory. If one of 
these conditions be wanting or any other unknown to us, then consciousness 
(a part of the whole) would disappear, and that which would remain of the fact 
is organized. Intensity is a degree of concentration which may vary, owing to 
the striving of our states of consciousness to supplant one another, and victory 
results either from the superiority of one or weakness of the other. Duration is 
the period between the impression and consciousness of it. Ribot says it requires 
0.16 to 0.14 of a second to hear; 0.21 to 0.18 of a second to touch, and 0.20 to 
0.22 of a second to see. This would indicate that the expression, "quick as 
thought," is a mere figure of speech. 
The acts of organized memory are performed unconsciously, involuntarily. 
The odor of food will sometimes cause an increased flow of saliva. When we 
were learning to walk our steps were taken with hesitancy and deliberation, — 
consciously ; now we walk without knowing it, our conscious memory through 
continual repetition, has become organized. If we meet an obstruction on the 
sidewalk we unconsciously move it to one side to avoid it. This is the result of 
VII— 39 
