Unfortunately today the gate was locked so it was not easy to get a good photo of this tombstone behind a tiny garden in Edinburgh. It is reputed to be the tomb of a 17th century apothecary, John Livingston, who bought the Greenhill Estate in 1636 on the south side of the Burgh Muir which then lay outside the Edinburgh boundary and had become the place to bury victims of the Plague. The tomb is a square area which was believed to have had a roof at one time and the stone is inscribed
MORS PATET HORA LATET
(meaning Death is certain the Hour unknown)

THIS SAINT WHOS CORPS LYES BU/RIED HEIR
LET ALL POSTERITIE ADMEIR
FOR VPRIGHT LIF IN GODLY FEIR
WHEN JUDGEMENTS DID THIS LAND / SURROUND
HE WITH GOD WAS WALKING FOUND
FOR WHICH OF MIDST OF FERS / HE'S CROUND
HEIR TO BE INTERRED BOTH HE
AND FRIENDS BY PROVIDENC AGRIE
NO AGE SHAL LOS HIS MEMORIE
HIS AGE 53 DIED / 1645
According to  Historic Scotland  John Livingston died in 1656 so it is unlikely to be his tomb
The date of the stone, 1645, suggests that it commemorates a victim of the virulent plague epidemic that swept through Edinburgh that year. If this is the case it has additional historic interest as one of a very small number of memorials (if not the only one) to survive from the time when plague victims had to be buried outwith the Edinburgh City Boundary. The enclosure is set back from the road at the rear of a small public garden beside 1 Chamberlain Road.
John Livingstone is variously described in records as a Merchant Burgess or Apothecary and purchased the lands of Greenhill House in 1636. He married Elizabeth Rigg in 1626 and is believed to have died in 1656. It is therefore improbable that the memorial stone relates to him, although the initials and shield, which is identical to that on the pediment (the initials on which presumably are those of John Livingstone and Elizabeth Rigg), indicates that the stone may have been for someone connected with the family
The extra show the entrance to the garden which is tended by the local community and a pleasant place in which to sit and relax.