An expert has said that a dozen Lewisite air bombs of the greatest size in use during 1918 might with a favorable wind have eliminated the population of Berlin. Possibly he exaggerated, but probably not greatly. The Armistice came; but gas research went on. Now we have more than a hint of a gas beyond Lewisite. It cannot be much more deadly; but in proportion to the amount of chemical which generates it, the spread is far greater. A mere capsule of this gas in a small grenade can generate square rods and even acres of death in the absolute. . . .
So much at present for gas. It is the new factor, the one which may hold the greatest promise for future improvement in war. But there has been much improvement in certain methods already known and used, which in future wars may be auxiliary to gas. There was the old, stock weapon of modern wars—the tube from which hard substances were projected by chemical explosion—in short, the gun. In proportion to initial cost, the power of the gun and of the auxiliary explosion its chemical had increased enormously. The smokeless TNT and other high explosives employed in this war were but little more expensive, pound for pound, than the old black powder of past wars; in effect they were incomparably more destructive. Men in war defended themselves against this increased destructive power by an old method made new; they burrowed deep into the inert earth. But even at that, destruction proceeded faster than the defence against destruc-
