mber best the things that you hear, you may find it a good plan
to read your lessons aloud. Many a student, upon the discovery of such
a preference, has increased his memory ability many fold by adopting
the simple expedient of reading his lessons aloud. It might be pointed
out that while you are reading aloud, you are making more than auditory
impressions. By the use of the vocal organs you are making muscular
impressions, which also aid in learning, as will be pointed out in
Chapter X.

After this discussion do not jump to the conclusion that just because
you find some difficulty in using one sense avenue for impression, it
is therefore impossible to develop it. Facility in using particular
senses can be gained by practice. To improve ability to form visual
images of things, practise calling up visions of things. Try to picture
a page of your history textbook. Can you see the headlines of the
sections and the paragraphs? To develop auditory imagery, practise
calling up sounds. Try to image your French instructor's voice in
saying _eleve_. The development of these sense fields is a slow and
laborious process and one questions whether it is worth while for a
student to undertake the labor involved when another sense is already
very efficient. Probably it is most economical to Arrange impressions
so as to favor the sense that is already well developed and reliable.

Another important condition of impression is repetition. It is well
known that material which is repeated several times is remembered more
easily than that impressed but once. If two repetitions induce a given
liability to recall, four or eight will secure still greater liability
of recall. Your knowledge of brain action makes this rule intelligible,
because you know the pathway is deepened every time the nervous current
passes over it.

Experiments in the psychological laboratory have shown that it is best
in making impressions to make more than enough impressions to insure
recall. "If material is to be retained for any length of time, a simple
mastery of it for immediate recall is not sufficient. It should be
learned far beyond the point of immediate reproduction if time and
energy are to be saved." This principle of learning points out the fact
that there are two kinds of memory--immediate and deferred. The first
kind involves recall immediately after impression is made; the second
involves recall at some later time. It is a well-known fact that things