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
Tanks in the German Army Panzer I. Production began in 1935, but it took another eighteen months for the first combat-ready tank to be delivered. It was also sent to Spain from 1937, and the PzKpfw II proved more capable against light infantry, but no better when faced with capable anti-tank guns or other tanks. Despite these weaknesses production continued until 1941, at the outbreak of war the German Army had 955 PzKpfw IIs and almost 4000 were built in total. A major boost to German armour came with the acquisition of Czechoslovakia in 1938, giving the entire Czech arms industry to Germany. The Czechs