nce of particular facts. One or two examples will illustrate
this difference. The late Dr. Addison Alexander, of the Theological
Seminary at Princeton, had memory as an intellectual power to a degree
almost marvellous. The following instance may be cited. On one occasion,
a large class of forty or fifty were to be matriculated in the Seminary
in the presence of the Faculty. The ceremony of matriculation was very
simple. The professors and the new students being all assembled, in a
large hall, each student in turn presented himself before the
professors, had his credentials examined by them, and if the same proved
satisfactory, entered his name in full and his residence, in the
register. When the matriculation was complete and the students had
retired, there was some bantering among the professors as to which of
them should take the register home and prepare from it an alphabetical
roll,--a work always considered rather tedious and irksome. After a
little hesitation, Dr. Alexander said, "There is no need of taking the
register home; I will make the roll for you;" and, taking a sheet of
paper, at once, from memory, without referring to the register, and
merely from having heard the names as they were recorded, he proceeded
to make out the roll, giving the names in full and giving them in their
alphabetical order. This was a prodigious feat of pure memory; for in
order to make the alphabetical arrangement in his mind, before
committing it to paper, he must have had the entire mass of names
present in his mind by a single act of the will. Some of the wonderful
games of chess performed by Paul Morphy are dependent in part upon a
similar power of memory, by which the player is enabled to keep present
in his mind, without seeing the board, a long series of complicated
evolutions, past as well as prospective and possible. The same is true
of every great military strategist.

In all these cases, there is an act of pure memory, a direct and
positive power of summoning into the mind its past experiences, such as
can only take place where, either by natural gift or by special
training, the memory as a faculty of the mind is in a high state of
vigor. But there are other cases, in which a man is enabled to recall a
great number of particular facts by a species of artifice or trick,
which does not imply any special mental power, and the study of which
does not tend, in any marked degree, to develop such power. More than
thirty years a