last battle under sail was the Battle of Navarino (1827), part of the Greek War of Independence, during which fireships were utilised by the Turks. Chemical warfare had been experimented with during the early period with sulfur, quicklime (calcium oxide), and others, and developments continued. World War I saw many gases used, including the extremely effective sulfur mustard (mustard gas). See also Petroleum Warfare Department Scorched earth Death by boiling Notes References Incendiary weapons Siege weapons Fortification weapons Anti-personnel weapons Medieval artillery Ancient weapons