CHEMICAL WARFARE

From the time when bows and arrows and similar weapons were replaced by firearms and the use of explosives the chemist has played an important role in the preparation of munitions of war. In fact, even in early times the use of chemicals for destroying or discomfiting the enemy was common, burning sulphur and similar materials being used in the ‘stink pots’ of the ancients. In its strictest sense, however, the term ‘chemical warfare’ covers the use of poisonous or irritating gases and the means of defense used against them, and the practice in its modern development dates from April 22nd, 1915, when the Germans first used chlorine in an attack upon the French Front, north of the Ypres salient. The chemical warfare division of an army is divided, to a more definite degree than other divisions, into an Offense Section and a Defense Section. It is the function of the former to devise gases. which shall be more deadly, and against which it shall be more difficult to provide protection, than those used by the enemy. It also comes within the duties of this section to develop and supervise the wholesale manufacture of the gas which it considers satisfactory, to carry out large scale tests of its toxicity and general usefulne , and to devise containers which will not be corroded by the gas. The Defense Section is chiefly concerned with providing the fighting units with protection azainst gas attacks. The commonest and most succe ful form of defense so far devised is the gas mask. This usually consists of a hood fitting loosely over the head and so devised that the air drawn into the body in the act of breathing has to pa through a canister filled with activated absorbent carbon and neutralizing chemicals. To increase the efficiency of this protection it is obviously nece ary to collect samples of the gases used by the enemy, to analyze them and on the basis of such analyses to prepare chemicals which shall neutralize or absorb the gases satisfactorily. The manufacture of such chemicals and of the absorptive carbon also form part of the functions of the Defense Section. A ‘war gas’ may be a liquid, a solid, a vapor or a true gas. Its value may depend either on its toxic properties, its power to produce tears, or nausea, or sneezing, its foul odor, or its capacity for forming a dense smoke. Gases having all these different properties were used n the European war. The gas must be effective in very small concentration, no gas being considered satisfactory which cannot produce the desired results in a concentration of one part per million of air. In the early days of the European war, the cloud attack was commonly used, the gases being liberated from tanks, or cylinders, and carried over to the enemy trenches by favorable winds. Such methods, however, were too uncertain in their results, and in the later years of the war gas was sent over in special shells and the use of cloud attacks was almost completely abandoned.