It follows from a consideration of the Law of Association that when one wishes to impress a thing upon the memory he should, as an authority says, "Multiply associations; entangle the fact you wish to remember in a net of as many associations as possible, especially those that are logical." Hence the advice to place your facts in groups and classes in the memory. As Blackie says: "Nothing helps the mind so much as order and classification. Classes are always few, individuals many; to know the class well is to know what is most essential in the character of the individual, and what burdens the memory least to retain."
Another important principle of memory is that the impressions acquire depth and clearness by repetition. Repeat a line of poetry once, and you may remember it; repeat it again, and your chances of remembering it are greatly increased; repeat it a sufficient number of times, and you cannot escape remembering it. The illustration of the phonograph record will help you to understand the reason of this. The rule is: Constant repetition deepens memory impressions; frequent reviewing and recalling what has been memorized tends to keep the records clear and clean, beside deepening the impression at each review.
The following general rules will be of service to the student who wishes to develop his memory: