Fleming spent his 1928 summer break at The Dhoon, his country home in Barton Mills, Suffolk. He stayed there with his family before returning to his London laboratory in early September.
Before leaving St Mary’s Hospital, Fleming had inoculated culture plates with Staphylococcus aureus. He set them aside on a laboratory bench, partly so that Stuart Craddock could use the workspace. During Fleming’s absence, one plate became contaminated with a mould.
On his return, Fleming and Daniel Merlin Pryce examined the plates and noticed that the bacteria surrounding the mould had been destroyed. The holiday at The Dhoon therefore forms part of the chronology of the discovery, but Fleming did not discover penicillin while walking around Suffolk or working in the house. The crucial observation took place at St Mary’s Hospital in London.
The Dhoon was in Barton Mills, near the River Lark, and Fleming owned the property from 1921 until his death in 1955. The house is commemorated locally with a plaque. Its name is sometimes confused with the names of other Fleming residences, but the Suffolk country home was The Dhoon.