cies--if we consider the divisions into vocal,
instrumental, and mixed; and their subdivisions into music for
different voices and different instruments--if we observe the many forms
of sacred music, from the simple hymn, the chant, the canon, motet,
anthem, &c., up to the oratorio; and the still more numerous forms of
secular music, from the ballad up to the serenata, from the instrumental
solo up to the symphony. Again, the same truth is seen on comparing any
one sample of aboriginal music with a sample of modern music--even an
ordinary song for the piano; which we find to be relatively very
heterogeneous, not only in respect of the variety in the pitches and in
the lengths of the notes, the number of different notes sounding at the
same instant in company with the voice, and the variations of strength
with which they are sounded and sung, but in respect of the changes of
key, the changes of time, the changes of _timbre_ of the voice, and the
many other modifications of expression. While between the old monotonous
dance-chant and a grand opera of our own day, with its endless
orchestral complexities and vocal combinations, the contrast in
heterogeneity is so extreme that it seems scarcely credible that the one
should have been the ancestor of the other.

Were they needed, many further illustrations might be cited. Going back
to the early time when the deeds of the god-king were recorded in
picture-writings on the walls of temples and palaces, and so constituted
a rude literature, we might trace the development of Literature through
phases in which, as in the Hebrew Scriptures, it presents in one work
theology, cosmogony, history, biography, law, ethics, poetry; down to
its present heterogeneous development, in which its separated divisions
and subdivisions are so numerous and varied as to defy complete
classification. Or we might trace out the evolution of Science;
beginning with the era in which it was not yet differentiated from Art,
and was, in union with Art, the handmaid of Religion; passing through
the era in which the sciences were so few and rudimentary, as to be
simultaneously cultivated by the same men; and ending with the era in
which the genera and species are so numerous that few can enumerate
them, and no one can adequately grasp even one genus. Or we might do the
like with Architecture, with the Drama, with Dress. But doubtless the
reader is already weary of illustrations; and our promise has been amply