Off a distance ahead I could see what looked like a long row of white fuses sticking up in the faint starlight. From them the fresh west wind seemed to blow a thick curtain of greenish-yellow smoke which swept across the track, enveloping the engine and the forward cars and now advancing toward us like the "yellow wind" of northern China. It seemed to spread thickly on the ground, rising scarcely more than sixteen or eighteen feet.
A moment and the cloud began to fill the air about us. There was a paralyzing odor. I looked about at the others, gasping and coughing. As the cloud rolled on, inexorably increasing in density, it seemed literally to grip the lungs.
It flashed over me that already the engineer and fireman had been overcome, though not before the engineer had been able to stop the train.
As the cloud advanced, the armed guards ran from it, shouting, one now and then falling, overcome. For the moment none of us knew what to do. Should we run and desert the train for which we had dared so much? To stay was death.
Quickly Kennedy pulled from his pocket the gauze arrangements he had had in his hand that morning just as Miss Euston's knock had interrupted his conversation with me. Hurriedly he shoved one into Miss Euston's hands, then to Lane, then to me, and to the guard who was with us.
"Wet them!" he cried, as he fitted his own over his nose and staggered to a water-cooler.
"What is it?" I gasped, hoarsely, as we all imitated his every action.
"Chlorin gas," he rasped back, "the same gas that overcame Granville Barnes. These masks are impregnated with a glycerin solution of sodium phosphate. It was chlorin that destroyed the red coloring matter in Barnes's blood. No wonder, when this action of just a whiff of it on us is so rapid. Even a short time longer and death would follow. It destroys without the possibility of reconstitution, and it leaves a dangerous deposit of albumin. How do you feel?"
"All right," I lied.
We looked out again. The things that looked like fuses were not bombs, as I had expected, but big reinforced bottles of gas compressed at high pressure, with the taps open. The supply was not inexhaustible. In fact, it was decidedly limited. But it seemed to have been calculated to a nicety to do the work. Only the panting of the locomotive now broke the stillness as Kennedy and I moved forward along the track.