compound
substances, to which chemistry daily adds, is so great that few, save
professors, can enumerate them; and to recollect the atomic
constitutions and affinities of all these compounds, is scarcely
possible without making chemistry the occupation of life. In the
enormous mass of phenomena presented by the Earth's crust, and in the
still more enormous mass of phenomena presented by the fossils it
contains, there is matter which it takes the geological student years of
application to master. Each leading division of physics--sound, heat,
light, electricity--includes facts numerous enough to alarm any one
proposing to learn them all. And when we pass to the organic sciences,
the effort of memory required becomes still greater. In human anatomy
alone, the quantity of detail is so great, that the young surgeon has
commonly to get it up half-a-dozen times before he can permanently
retain it. The number of species of plants which botanists distinguish,
amounts to some 320,000; while the varied forms of animal life with
which the zoologist deals, are estimated at some 2,000,000. So vast is
the accumulation of facts which men of science have before them, that
only by dividing and subdividing their labours can they deal with it. To
a detailed knowledge of his own division, each adds but a general
knowledge of the allied ones; joined perhaps to a rudimentary
acquaintance with some others. Surely, then, science, cultivated even to
a very moderate extent, affords adequate exercise for memory. To say the
very least, it involves quite as good a discipline for this faculty as
language does.

But now mark that while, for the training of mere memory, science is as
good as, if not better than, language; it has an immense superiority in
the kind of memory it trains. In the acquirement of a language, the
connections of ideas to be established in the mind correspond to facts
that are in great measure accidental; whereas, in the acquirement of
science, the connections of ideas to be established in the mind
correspond to facts that are mostly necessary. It is true that the
relations of words to their meanings are in one sense natural; that the
genesis of these relations may be traced back a certain distance, though
rarely to the beginning; and that the laws of this genesis form a branch
of mental science--the science of philology. But since it will not be
contended that in the acquisition of languages, as ordinarily carried
on, these na