[texhax] Footnotes in separate file

[Nicholas Cole]

Dear List,

I'm trying to streamline my workflow a little.  Since I work in the
humanities, many of my footnotes, which are frequent, are fairly
extensive.  This tends to disrupt the flow of the document on the
screen and makes editing the text itself harder.  One solution I'm
considering is putting all of the footnotes in a separate file (or
perhaps at the end of the main file).  What envisage is having
something like:

This is some text.\fn{5}

in one file, and then having

\deffn{5}{This is the footnote text}

in another file.

Is there already a package to do something similar? What would be the
most robust way to go about something like this?

Any advice appreciated!

Best wishes,

Nicholas