Chemical weapons in World War I volatile oily liquid. It was introduced as a vesicant by Germany in July 1917 prior to the Third Battle of Ypres. The Germans marked their shells yellow for mustard gas and green for chlorine and phosgene; hence they called the new gas "Yellow Cross". It was known to the British as "HS" ("Hun Stuff"), and the French called it "Yperite" (named after Ypres). Mustard gas is not an effective killing agent (though in high enough doses it is fatal) but can be used to harass and disable the enemy and pollute the battlefield. Delivered in artillery shells, mustard gas was
Mines in the Battle of Messines (1917) Mines in the Battle of Messines (1917) The mines in the Battle of Messines comprised a series of underground explosive charges, secretly planted by British tunnelling units beneath the German 4th Army lines near the village of Mesen ("Messines" in French, historically used in English) in Belgian West Flanders during the First World War. The mines were detonated at the start of the Battle of Messines , creating craters. The joint explosion of the mines at Messines ranks among the largest non-nuclear explosions of all time. The evening before the attack, General Sir Charles Harington, Chief of Staff of the