How does Dickens blend comedy and horror in A Christmas Carol?

One of the great abilities of Dickens as a writer is the
way that he is able to mix horror and ironic comedy together in his work, and this can
certainly be seen to be in operation in this great seasonal classic. You will want to
consider how the presentation of the ghosts is juxtaposed with humorous commentary
concerning the character of Scrooge and how he typically acts. Let us take an example to
see this in play. When the Ghost of Christmas Past appears, for example, it is with
typical nonchalance or selfishness that Scrooge first asks to cover up the Ghost so that
he could see the Spirit "in his cap," then, when he asks the Ghost why he is there, and
receives the response "Your welfare," responds ironically to the
Ghost:

Scrooge
expressed himself much obliged, but could not help thinking that a night of unbroken
rest would have been more conducive to that
end.

The idea of Scrooge
taking issue with the horrible ghost shows something of his hard-bitten defiance and
selfishness, which interlaces humour with horror in a particularly Dickensian
way.