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
Normal type Normal type Normal type (in German: "Normaltyp") is a typological term in sociology coined by the German sociologist Ferdinand Tönnies (1855–1936). It can be considered both as a forerunner of, and a challenge to, the rather better known concept of Max Weber’s: the ideal type (in German "Idealtyp"). Tönnies drew a sharp line between the realm of conceptualization (of sociological terms, including ‘normal types’) and the realm of reality (of social action). The first must be treated axiomatically and in a deductive way (pure sociology); the second, empirically and in an inductive way (applied sociology). Following Tönnies, reality (the second