According to the 1873 Guide to the Church this memorial was originally sited in the North Transept, an area now largely occupied by the organ. It is believed that the memorial remains in situ behind the organ.
Memorial


(From the 1873 Guide)
SACRED TO THE MEMORY OF JOHN HUME, SURGEON, OF HIS MAJESTY'S 59TH REGIMENT WHO DEPARTED THIS LIFE THE 12TH AUGUST 1828 IN THE 48TH YEAR OF HIS AGE