http://books.google.com/books?id=_RYuIK5P6IsC&pg=PA123&lpg=PA123&dq=why+was+black+powder+in+mexico+poor+quality&source=bl&ots=mQxlygiPmM&sig=XboMISGJ8p2ao7i16A8TQGzYJEw&hl=en&ei=U6J8TvidOOOqsQL5-IA6&sa=X&oi=book_result&ct=result&resnum=2&ved=0CCQQ6AEwAQ#v=onepage&q&f=false
Jim