Concatenated XML files

I have a set of USPTO xml files that I am trying to process using
Xerces-C.  Unfortunately, it seems as though these files were created
by merely concatenating together a number of smaller xml files.

Xerces has an error as soon as it gets to the second <?xml element
(not valid after content).

What do I do?  Is there some way to get xerces-c to allow this?
--
Justin W. Hart