496 On Memory. 
violent passions will tumble them out of their secret cells. 
This faculty other animals seem to have to a great degree, 
as well as man, as appears by birds learning tunes, and 
their attempts to hit the right notes; for it seems impossible 
that they should endeavour to conform their voices, as it is 
plain they do, to notes of which they have no idea, 
One of the most remarkable instances of this power of 
remembering tunes in birds, is related of Colonel Kelly’s 
parrot. The Colonel was at Brighton; the bird was asked 
to sing; he answered, “I can’t ;’ another time he left off in 
the middle of atune and said “I have forgot.” Colonel 
Kelly continued the tune for a few notes, and the bird took 
it up where the Colonel left off. 
There have been, and still are, many other theories of 
memory. Descartes, Rene, the philosopher of La Haye 
Tourain, and his followers, maintain that “the animal spirits, 
exciting a motion in the most delicate fibres of the brain, 
leave traces or footsteps which occasion remembrance; 
hence it happens that by passing several times over the 
same things the spirits become accustomed to the same 
passages, leave them open, and so make their way without 
any effort or labour, and in this consists the ease with 
which we recollect such ideas. Thus wine is found to 
sharpen the memory, because wine puts the animal spirits 
in motion, and agitates the fibres of the brain more 
briskly.” 
Father Nicholas Malbranche, a French philosopher, ob- 
serves :—“It being granted that all our different percep- 
tions are owing to changes happening in the fibres of the 
principal parts of the brain, wherein the soul more imme- 
diately resides, the nature of the memory is obvious, for as 
the leaves of a tree that have been folded for some time in 
a certain manner preserve a facility or disposition to be 
folded again in the same manner, so the fibres of the brain 
having once received certain impressions by the courses of 
the animal spirits, and by the action of objects, preserve for 
some time a facility to receive the same disposition. Now 
it is in this facility that memory consists, for we think the 
same things when the brain receives the same impressions. 
Further, as the animal spirits act sometimes more briskly 
and sometimes more slowly on the substance of the brain, 
and as sensible objects make much deeper and more last- 
ing impressions than the imagination alone, it is easy on 
this scheme to conceive why we do not remember all things, 
why a thing, for instance, seen twice, is represented more 
