The last or accidental emphasis is laid on a word when it has some particular meaning, and when the force of a sentence depends on it; this therefore requires an elevation of voice; as,
"Perdition catch my soul—but I do love thee."
So far the prosody of the English language seems to be settled; but the rules laid down for the construction of verse, seem to have been imperfect and disputed.
Writers have generally supposed that our heroic verse consists of five feet, all pure Iambics, except the first foot, which they allow may be a Trochee. In consequence of this opinion, they have expunged letters from words which were necessary; and curtailed feet in such a manner as to disfigure the beauty of printing, and in many instances, destroyed the harmony of our best poetry.
The truth is, so far is our heroic verse from being confined to the Iambic measure, that it admits of eight feet, and in some instances of nine. I will not perplex my readers with a number of hard names, but proceed to explain the several feet, and show in what places of the line they are admissible.
An Iambic foot, which is the ground of English numbers, consists of two syllables, the first short and the second long. This foot is admitted into every place of the line. Example, all Iambics.
"Whĕre slāves ŏnce mōre thĕir nātĭve lānd bĕhōld,
Nŏ fiēnds tŏrmēnt, nŏ chrīstiăns thīrst, fŏr gōld."
Pope.
The Trochee is a foot consisting of two syllables, the first long and the second short. Example.