go, the late Professor Dod, of Princeton College, in
lecturing to a class on the subject of light, was explaining the solar
spectrum, and after exhibiting the solar ray, divided into its seven
primary colors, violet, indigo, blue, green, yellow, orange, and red,
said, "If you will form a mnemonic word of the first letters of each of
these words, you will be able, without further effort, to remember the
order of the prismatic colors the rest of your lives," and he
accordingly wrote upon the board and pronounced the uncouth and almost
unpronounceable word, _Vibgyor_, which probably not one of us has ever
forgotten. An ingenious Frenchman some years ago traversed the country
and collected large audiences by his exhibitions of skill in this
species of artifice, and by undertaking to initiate his hearers in the
method of remembering prodigious numbers of historical facts by means of
such artificial contrivances. Mnemotechny, the name which he gave to his
invention, is merely a trick of the memory. It is a means of remembering
a particular set of facts or things by the aid of contrivances purely
artificial and arbitrary. Its possession does not imply, and its
cultivation does not produce, real mnemonic power. It undoubtedly has
its uses. But it is rather wealth gained by a lottery ticket than a
wealth-producing power acquired by wise habits of business.

In teaching the young, it is well not to neglect either of these
principles. We should give our children from time to time ingenious and
interesting contrivances for remembering important facts. These
contrivances, if judicious in plan and execution, will be great helps
to them. We may in this way bridge over the difficulty of remembering
many of the important facts and dates in history.

I would not discourage these artificial methods. Though they are mere
tricks, they are valuable. But they have by no means the same value as
those methods of teaching which cultivate and produce true mnemonic
power. This power, like every other mental power, is given in unequal
measure to different individuals. Like every other mental power, also,
it grows mainly by exercise. No power of the mind is more capable of
development. I have mentioned some things which tend to the growth of
this power, such as presenting knowledge to children in logical and
orderly arrangement, and frequent re-examination of knowledge already
obtained. Perhaps there is no quickener and invigorator of the memory
eq