"Fifteen people on the dead man's chest": what is being sung in a pirate song?

The famous song, known by the novel of Robert Louis Stevenson's "Treasure Island", tells of the real events that happened on board the ship "Revenge of Queen Anne". This 40-gun frigate belonged to the cruel pirate Edward Tich, nicknamed Blackbeard (in the illustration). The commander of the boarding team, William Bones (who in Stevenson turned into Billy Bons) once raised a riot against Tich, but was defeated. Fifteen instigators Blackbeard ordered to land on a tiny uninhabited island Dead Man's Chest in the Virgin Islands, and on parting each disgraced pirate received a bottle of rum. The latter, by the way, was a sophisticated mockery: there are no sources of fresh water on the island, and you can not quench your thirst with rum: you can only light it.