 After the War , most of the young men left the island , and the population fell from 73 in 1920 to 37 in 1928 . After the death of four men from influenza in 1926 , there was a succession of crop failures in the 1920s . Investigations by the University of Aberdeen into the soil where crops had been grown have shown that there had been contamination by lead and other pollutants , caused by the use of seabird carcasses and peat ash in the manure used on the fields . This occurred over a lengthy period of time , as manuring practices became more intensive , and may have been a factor in the evacuation . The last straw came with the death of a young woman , Mary Gillies , who fell ill with appendicitis in January 1930 and was taken to the mainland for treatment . She later died in hospital . For many years it was assumed that she had died of appendicitis , but her son Norman John Gillies discovered in 1991 that she had in fact died of pneumonia , having given birth to a daughter who also died . On 29 August 1930 , a ship called Harebell took the remaining 36 inhabitants to Morvern on the Scottish mainland , a decision they took collectively themselves . 
