From a little pin prick which he made on his own thumb Craig squeezed out a drop of blood into a beaker containing some distilled water.
“This is a spectroscope,” he explained, touching the instrument I had noticed. “I think you are acquainted with it in a general way. Blood in water, diluted, shows the well-known dark bands between what we call ‘D’ and ‘E.’ These are the dark bands of oxyhemoglobin absorption. Now, I add to this, drop by drop, the water from that bottle which I uncorked. See—the bands gradually fade in intensity and finally disappear, leaving a complete and brilliant spectrum devoid of any bands whatever. In other words, here is a substance that actually affects the red coloring matter in the blood, bleaches it out, and does more—destroys it.”
I listened in amazement at the fiendish nature of his discovery.
“Marshall Maddox was overcome by the poison gas contained in a thin-shelled bomb that was thrown through his state-room window. The corrosion of the metal in the room gave me a clue to that. Then—”
“But what is this poison gas?” I demanded, horrified.
Kennedy looked at me fixedly a moment. “Chlorine,” he replied, simply; adding, “the spectroscope shows that there is a total absence of pigment in the blood. You can readily see that it is no wonder, if it has this action, that death is sometimes so rapid as to be almost instantaneous. Why, man alive, this thing destroys without the possibility of reconstitution! It is devilish in the quantity he inhaled it.”
I could only gasp with surprise at the discovery.
“But how was it done?” I repeated. “You think a bomb was thrown through the open port?”
“Without a doubt. Perhaps, as you guessed, from a boat outside, the roof of a cruiser, anything, as far as that end of it goes. Whoever did it might also have entered the room in the same way.”
“Entered the room?” I asked.