effectiveness, has caused an outcry when first introduced. Gas warfare, per se, is not necessarily or exceptionally cruel. For instance, if it were conducted on both sides with cyanides, suc- cessfully adapted to war purposes, the resultant deaths would be the most merciful that history has ever known. It is to be noted that in the World War less than 3 % of the total gas casualties were deaths, whereas some 20 % of casualties due to other weapons resulted in death either on the field or in hospital. The use of gases may be guarded by future conventions so as to prevent unnecessary suffering, just as explosive bullets were barred. Thus chlorine might be forbidden, because there is no death more painful than that by suffocation. But the utmost that seems possible is to limit by convention the use of poison gases in such a way that a breach of the convention will not place the offending combatant in a definite position of superiority.
It is infinitely to be deplored that gas warfare was ever intro- duced. It certainly adds a new horror to war. It imposes fresh burdens on the soldiers, who may ultimately be forced to spend most of their time in gas masks, even when far behind the lines. The most terrible thing perhaps about it is that, since it is im- possible to remove all non-combatants from a zone of war, and equally impossible to provide them with masks, thousands of them must inevitably perish. For this reason alone it would be well if gases were forbidden. To forbid them, however, is one thing; to prevent their use is another. And unless more effectual means than were within sight in 1921 can be devised to make this (or any other) form of warfare impossible, considerations of national security must inevitably prevail.
Gases used in the World War. The following are some of the more important gases used during the World War:
Cyanogen Compounds. Effect, in concentrations of as much as I in 1,000, immediate death. In weak concentrations, giddiness, headache and pains about the heart, but ultimately complete recov- ery. Used by the French and the British in shells as a mixture of 50% hydrogen cyanide, with arsenic trichloride, stannic chloride and chloroform.
Chlorine. Attacks the respiratory tracts, forming in contact with moisture hydrochloric acid which destroys the tissues. Has a reflex action on the system generally, causing vomiting and diar- rhoea. In high concentration may cause immediate death by spasm of the glottis. Only used as cloud-gas from cylinders.
Phosgene (Carbonyl chloride). A very dangerous gas because the effect is delayed, and the victim is often not aware that he has been gassed. May cause sudden death as much as 48 hours after exposure. Very much used both in shells, and with chlorine as cloud-gas.
Diphosgene (Trichlormethyl chloroformate). Effect similar to that of phosgene. Much used in shells, both alone and with other gases.
Chloropicrin. Acts on the respiratory system like chlorine but more strongly. Is also a lachrymator. Much used in shells gener- ally in combination with other gases.
Bromine. Action similar to that of chlorine. It can be used conveniently for gas-clouds on account of its high boiling-point, but it forms the basis of a large number of powerful lachrymators. It was much used by the Germans as a lachrymatory shell-filling in the form of benzyl or xylyl bromide and brominated ketones.
Ethyl iodoacetate. British lachrymator. Very marked action on the eyes, ceasing the moment the neighbourhood of the gas is left. High persistence.
Bromacetone, Chloracetone and Brommethylethylketone. Much used in shell. Powerful lachrymators, and asphyxiating or lethal in high concentrations. Moderate persistence.
Diphenylchloroarsine. Solid, dispersed in clouds of fine particles. Cannot be kept out by ordinary masks. Powerful sternutator, pro- ducing also coughing and sickness; in strong concentration, causing insupportable headache. Much used in Blue Cross shells by the Germans.
Diphenylcyonoarsine. Similar to diphenylchloroarsine, but with a more powerful action. It superseded the latter as a German Blue Cross filling.
Mustard Gas, Yperite, or Yellow Cross. (Sym. dichlordiethylsul- phide). Vesicant. Attacks the skin even through the clothing with a blistering or burning effect. Affects all the mucous surfaces. Acting on the eyes causes blindness, usually temporary. Acting on the respiratory tracts may cause death by bronchial pneumonia. In favourable weather remains effective for several days.
Livens Projectors. The use of lethal-gas shells, which require a very high concentration, implies the necessity of bursting a large number of shells simultaneously along a given length of trench or over a given area. With artillery shell this necessitates a concen- tration of every available gun within range on the point of attack,
and needs a certain amount of preliminary arrangements. With Stokes or trench-mortar bombs whose contents are much larger, and especially with a Stokes gun which can be fired very rapidly, a smaller number of pieces can be used. But probably the most effective means of obtaining a high concentration was the pro- jector devised by Captain Livens, R.E. This consisted originally in using an old gas cylinder, with its top cut off, as a mortar; a hole is dug in the ground and the projector placed in it, resting on the ground at an inclination of 45 degrees and pointing in the required direction; the breech of the cylinder is backed up with a strong base-plate about 12 in. square. The propelling charge is contained in a tin box placed at the bottom of the projector and divided into compartments; the propellent explosive is placed in the compart- ments in bags, the number of bags being varied according to the range required. The projectile is a steel drum with rounded ends, 21 in. in length and just fitting into the cylinder, which has a bore of 8 in. ; within the drum is a central tube running down its length, about I in. in diameter, which contains the bursting charge. The projector is fired by an electric fuse, about 20 of them being con- nected up with an exploder. These 20 may all be placed side by side in the same trench, and will constitute a battery. By these means as many as 4,000 of these projectors have been placed in posi- tion behind the front trenches in a night and fired simultaneously. Naturally, neither range nor direction are very accurate, but they are sufficiently so to give a very high concentration of gas over a small area, in some cases sufficient to kill men even when wearing their respirators. These projectors proved so useful that they were employed also for incendiary and high-explosive charges, and were immediately copied by the Germans, who feared them more than any of the other chemical warfare methods of offence employed by the Allies.
Incendiary Materials. The beginning of the war showed nothing particularly new or useful in the incendiary materials used by either side. Quite early in the war a German incendiary shell was found to contain white phosphorus and a very inflammable celluloid mix- ture. In England petrol bombs were tried and containers filled with rags soaked in petrol. The results were not important. Phosphorus by itself was not a reliable incendiary agent, though a shower of molten phosphorus descending from a shell burst in the air had a good moral effect.
The first demand for incendiary materials for the British army arose from the necessity of burning the long grass in No Man's Land during the summer of 1915, to prevent the enemy from using it for cover. To meet this demand a small catapult grenade filled with phosphorus and petrol was supplied, it being found that a small addition of phosphorus gave a more certain ignition of the petrol. Phosphorus, however, was far more useful as a smoke-producer than as an incendiary. A very important advance was made when a method of utilizing thermit in shell was discovered. Thermit is a mixture of iron oxide and aluminium which when ignited by a suit- able primer burns with an intense heat, which has been estimated at 5400 Fahrenheit. It is used commercially for welding, and has been used in the army for such purposes as destroying guns, a small quantity of it being placed in the bore and ignited ; the result of this is to make the gun useless, as when the thermit cools it is found to be firmly welded to the surface of the bore.
The ordinary ignition, however, is too slow for the purpose of an incendiary shell. Experiments were made with special ignition pow- ders in Stokes shells but without good result. In Jan. 1916, however, thermit was tried with a bursting charge of ophorite which gave excellent results, the thermit being instantly raised by the dis- charge to melting-point so that when the shell was burst in the air it let fall a shower of molten metal. Ophorite was an explosive that had recently been discovered by Professor Thorpe, which while less powerful than the ordinary high explosives, had the advantage that it could be fired by a fuze without a detonator.
Thermit employed in low-velocity projectiles such as Stokes gun shells became a very valuable incendiary agent; with artillery shells it was not so useful, as satisfactory ignition was difficult to obtain.
Experiments were also tried with fine coal-dust distributed in the air but the results were not practical.
Anti-gas Defences. About the end of March 1915, in conse- quence of the increasing rumours that the Germans intended to use poison gases, the British War Office asked Sir William Ram- say's committee to consider what gases might possibly be used, and what would be the best means of protection. Before the committee reported, the cloud attack of April 22 was made. The circumstances were explained to Sir William Ramsay by telephone, with the remark that the gas was probably chlorine, and the next morning he came to the War Office with several sample mouth-pads made of flannel or wool soaked in hyposul- phite of soda. An appeal was made through the Press to British women to furnish 1,000,000 of them at once, and thanks to their response and the efforts of the Red Cross the necessary quantity came in two or three days, so that within a fortnight every man
