The man who would have faced a hostile House without a tremor now sank into his chair, deathly white and unnerved. It did not need more explanation to enable his keen, far-seeing brain to visualize the awful possibilities of my discovery. Yet I could see that he was struggling to disbelieve me.
"'It—it's incredible!' he gasped at last. 'Why, if what you say is true——'
"'Why waste words? Words may sway the thoughts and actions of men, but the most transcendent eloquence is powerless to affect the elements of nature. Compare those sets of symbols, and tell me honestly if you—without the assistance of a chemical expert—could say offhand which represents, say, creatine, the crystalline substance which is contained in your own muscles at this present moment, and the high explosive which goes by the name of devastite. Consider again that the very air we breathe consists of four-fifths of nitrogen—and it is scarcely necessary to remind a man occupying your post that nitrogen forms the basic principle of almost every explosive known. Then ask yourself whether it is beyond the power of modern science to make practical use of those facts. I know that you will probably remind me, in your turn, that the use of that particular explosive, devastite, has been discontinued because it has been found liable to detonate spontaneously through decomposition. But my answer is, that such a defect is a defect only so long as the explosive is within our lines—the moment it is within the enemy lines, the more easily it explodes the better! Each soldier in the vast armies arrayed against us contains within himself the means of his own destruction. It but needs one single element, harmless in itself, to be incorporated in a gas and sent over the enemy trenches, and the next few hours would see a holocaust such as the world has never known.'
"For a long time my companion looked at me without speaking. 'So that was your idea?'
"I felt myself flush at his tone. 'It certainly was my idea, but I abandoned it.'
"'Why?' he asked quickly.
"'It was too horrible, too fiendish, too frightful——'
"'Frightful?' He pounced on the word like a swooping hawk. 'Do you know who has taught us that word? Who has advocated the doctrine of ruthless frightfulness, backing it up with specious arguments that the most terrible weapons are the most merciful because they make the struggle of opposing nations shorter? Our foes have taught us that—and now they shall be confounded by their own text—"hoist with their own petard" in real earnest! Put whatever price you please on your own services—we must have that gas! I hope, I pray that we may never need to employ it, but we must have it—or the knowledge of its preparation—to use as a last resort.'
"I will not weary you with a recapitulation of the arguments he employed before I consented to renew my researches. But I made one stipulation. The secret of the gas must remain in my own possession, contained in a sealed envelope that would only be handed to him when I was convinced that no other alternative remained than the complete destruction of the British Empire. But fortunately I was not called upon to make that momentous decision, for when the United States of America became our allies there was very little doubt as to the ultimate result of the war.
"The peril has passed—but has it passed for all time? If I could have answered that question with an unhesitant
