BOSTON — Workers at the State House on Thursday morning chiseled away at a cornerstone of the building in an attempt to unearth a time capsule that was first buried in 1795.

The time capsule dates back to the building of the current State House. It was placed by then-Governor Samuel Adams, Paul Revere and William Scollay in a ceremony that started at the old State House and processed to the grounds of the current building, according to information provided by the Executive Office for Administration and Finance, which oversees the state's Division of Capital Asset Management and Maintenance.

Secretary of State William Galvin said the capsule was placed as part of a Masonic ritual.

The contents are expected to include coins from between 1652 and 1855, an engraved silver plate, newspapers, a seal of the Commonwealth, cards, and a title page from the Massachusetts Colony Records.

The capsule was last unearthed in 1855 during emergency repairs. Material from that time was added to the capsule before it was replaced by then-Governor Henry Gardner and sea captain and engineer Winslow Lewis.

The capsule lay inside the stone undisturbed until recently when workers for the Division of Capital Asset Management and Maintenance identified a water leak that was damaging the State House – and potentially the time capsule.

The capsule is expected to be removed from the stone Thursday and opened next week.

The Museum of Fine Arts will restore and preserve it.

Galvin said the capsule will be replaced some time next year, possibly with "a few extra contents."