Gathering historical information from gravestones is a tough job because inscriptions are being lost through lack of care, historian Ting Sun-pao says. His view is backed by gravestones restoration expert Paul Harrison, who warns that precious historical data will be lost forever if the gravestones are not cleaned and restored quickly The government has been urged to take care of forgotten historic graves, but the Food and Environmental Hygiene Department says it can manage only the public areas of cemeteries as the graves are 'private property'. 'The grave of Sir Kai Ho Kai is wearing out and the words on the Cornwallis monument can hardly be read now,' Dr Ting said, referring to the monument that commemorates the flagship HMS Cornwallis, which took part in the first opium war. Dr Ting said inscriptions were being eroded by bacteria, posing a challenge for historians who study them. He hoped the government would follow the example of the Jewish Cemetery at Happy Valley, which hired experts to clean and restore the memorial stones. Mr Harrison, who helped restore the privately run Jewish Cemetery, said it was the government's duty to care for historic gravestones. 'The graves need minimum care,' he said. 'At least for those fallen apart, they should be reattached to make sure they are safe to visitors.' He said gravestones were damaged by rainwater that accumulated in the cracks. 'Acid rain caused by air pollution is also chewing up the words and images on the marble.' Conservationists warned earlier this year that visitors could be killed by falling tombstones in Hong Kong Cemetery if the government did not restore and maintain them properly. They urged the government to follow the examples of Canada and Scotland, which have guidelines for proper restoration of tombstones and better management of cemeteries.