CHEMICAL WARFARE

the use of chemical compounds, usually toxic agents, in warfare, and also the methods of combating such agents. Though smoke, which is used for camouflage or to confuse an enemy, and incendiary weapons are covered by this definition, the term usually refers to the use of chemical agents, both lethal and nonlethal, which attack the human organism by paralyzing the nervous system (nerve gases); inducing temporary blindness, deafness, paralysis, nausea, or vomiting; causing severe burns to skin, eyes, or lungs; or stifling respiration. Also included are chemical defoliants and herbicides for military purposes, such as those used in the Vietnam War. World War I saw the first significant use of chemical warfare. From 1915 to 1918 the Germans introduced a succession of poison gases, each of which was promptly duplicated on the Allied side. In January 1915 the Germans released chlorine gas against the Russians in Poland with little effect, but on April 22 they scored a tactical victory against the French and British in Flanders that went beyond their expectations. The Allies first improvised protective devices and then developed gas masks, while at the same time producing their own chlorine. When the Germans introduced phosgene, a more lethal type of choking gas, and gas projectiles fired by artillery, the Allies followed suit and also improved their gas masks. In 1917 the Germans introduced mustard gas-a vesicant (blistering agent) compounded from carbon, hydrogen, sulfur, and chlorine-and in 1918 both sides used the new poison on a large scale. Though it inflicted numerous casualties, especially when a bombardment achieved a measure of surprise, the casualties were generally not severe, with relatively few fatalities. The universal revulsion against gas warfare, combined with its indecisive tactical effect, produced a virtual outlawing of the weapon that held good through World War II, when both chemical agents and their means of delivery (e.g., air bombardment) had vastly improved. Both sides produced poison gases, as well as protective devices, in quantity, and troops were universally provided with gas masks. One major breakthrough was made-the development in Germany of nerve gases, which proved far more toxic than the World War I agents-but was never used. Other poison gases known to have been produced in various countries include several known as blood gases because they interfere with functioning of the blood and utilization of oxygen by body tissues. Lacrimators (tear gases), widely employed by police in riot control, have also had occasional military applications. In high concentration they can produce serious irritation of the respiratory tract and of the skin, especially moist areas. The principal ingredients in gas-mask filters are charcoal and soda lime. Charcoal absorbs and holds a large volume of gas, while soda lime neutralizes toxic materials released by the charcoal. Gas masks are usually also provided with some form of mechanical filtration to strain out finely divided solid particles. the use of chemical compounds, usually toxic agents, in warfare, and also the methods of combating such agents. Though smoke, which is used for camouflage or to confuse an enemy, and incendiary weapons are covered by this definition, the term usually refers to the use of chemical agents, both lethal and nonlethal, that attack the human organism by paralyzing the nervous system (nerve gases); inducing temporary blindness, deafness, paralysis, nausea, or vomiting; causing severe burns to skin, eyes, or lungs; or stifling respiration. Also included are chemical defoliants and herbicides for military purposes, such as those used in the Vietnam War. Worldwide revulsion toward chemical weapons is embodied in the Geneva Protocol of 1925, prohibiting "the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices." More than 140 states, including all major nations, are parties to the Protocol of 1925. Matthew Meselson J.P. Perry Robinson Additional reading Chemical weapons are addressed in Frederick J. Brown, Chemical Warfare: A Study in Restraints (1968, reprinted 1981); L.F. Haber, The Poisonous Cloud: Chemical Warfare in the First World War (1986); United Nations, Chemical and Bacteriological (Biological) Weapons and the Effects of Their Possible Use: Report of the Secretary General (1969); World Health Organization, Health Aspects of Chemical and Biological Weapons (1970); Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare: A Study of the Historical, Technical, Military, Legal, and Political Aspects of CBW, and Possible Disarmament Measures, 6 vol. (1971-75); and Matthew Meselson and Julian Perry Robinson, "Chemical Warfare and Chemical Disarmament," Scientific American, 242(4):38-47 (April 1980). Matthew Meselson J.P. Perry Robinson