its wings where it may indulge its own impulses--

"Sailing with supreme dominion
Through the azure deep of air--"

without being stopped, or fretted, or diverted with the abruptnesses and
petty obstacles, and discordant flats and sharps of prose, that poetry
was invented. It is to common language, what springs are to a carriage,
or wings to feet. In ordinary speech we arrive at a certain harmony by
the modulations of the voice: in poetry the same thing is done
systematically by a regular collocation of syllables. It has been well
observed, that every one who declaims warmly, or grows intent upon a
subject, rises into a sort of blank verse or measured prose. The
merchant, as described in Chaucer, went on his way "sounding always the
increase of his winning." Every prose-writer has more or less of
rhythmical adaptation, except poets, who, when deprived of the regular
mechanism of verse, seem to have no principle of modulation left in
their writings.

An excuse might be made for rhyme in the same manner. It is but fair
that the ear should linger on the sounds that delight it, or avail
itself of the same brilliant coincidence and unexpected recurrence of
syllables, that have been displayed in the invention and collocation of
images. It is allowed that rhyme assists the memory; and a man of wit
and shrewdness has been heard to say, that the only four good lines of
poetry are the well known ones which tell the number of days in the
months of the year.

"Thirty days hath September," &c.