One thing I've noticed about Dickens' prose is that he'll often break into what basically amounts to disguised blank verse. If you read Dickens' descriptive passages, they often have an iambic rhyhm and break down into what amounts to lines of verse; sometimes the usual ten syllables, sometimes eight, sometimes twelve. It's not actually poetry disguised as prose; there is no strict verse form or line length being followed, and Dickens doesn't use the iambic rhythm all the time -- but he does it often enough to suggest that he was doing it on purpose. Here are a few passages from Martin Chuzzlewit rearranged as verse:
...each bearing on his back a bursting chest
poured slowly through the narrow passages;
while underneath the archway by the public-house,
the knots of those who rested and regaled within,
were piled from morning until night.
Strange solitary pumps were found near Todgers's
hiding themselves for the most part in blind alleys...
Oh, ermined Judge whose duty to society
is, now, to doom the ragged criminal
to punishment and death,
hadst thou never, Man, a duty to discharge
in barring up the hundred open gates
that wooed him to the felon's dock,
and throwing but ajar
the portals to a decent life!
The Temple fountain might have leaped up twenty feet
to greet the spring of hopeful maidenhood,
that in her person stole on, sparkling,
through the dry and dusty channels of the Law...
It seems like Dickens turned to poetic rhythms and (to some extent) poetic line-lengths when he wanted to write in a heightened style, whether for a description or one of his Stirring Invocations. It's an interesting technique that has never quite been abandoned; a 20th-century example of the technique can be found in the play The Lion in Winter by James Goldman, where many of the lines are iambic blank verse disguised as prose.