"Now look," he said.
We did. Something had evidently happened. The chains were broken and smaller units were moving.
"If anthrax germs are exposed for a few seconds, even, to ultra-violet light, they change more or less," Kennedy proceeded. "These new forms are not stable. They quickly change back again into their original form."
For about ten minutes we sat in silence while the weird light played as if with ghostly fingers on the deadly invisible peril on the little glass microscope slide.
"But if the action of the ultra-violet rays is continued," went on Craig, "the microbe changes into a coccus, and then into a filiform bacillus. This form is stable. And the germ is changed in other respects than mere shape. It has entirely new characteristics. It is a true mutation. It produces a disease entirely different from that of the anthrax bacillus from which it is derived. I have tried it on a guinea pig—and it has died in forty-eight hours."
Startled as I was by this remarkable discovery, I yet had time to watch Haynes. He had not taken his eyes off Kennedy once since he began to speak.
"In anthrax," continued Craig, "an autopsy reveals an enormous serous swelling, about the point of inoculation, with a large gathering of microbes which are formed in the blood and spleen. Death seems to be due to septic poisoning. But this new microbe—super-toxicus, I think it might well be named—produces no swelling and scarcely any microbes are to be found in the blood.
"The lungs are inflamed, with innumerable small abscesses. That is the internal form of the disease from breathing in the spores of these microbes. It has an external form, also, but that is by no means so deadly. One would say that death from the internal form of the disease was due to poisoning. The toxin of this microbe produces a sort of asphyxiation, cutting off and eating up the supply of oxygen.
"Such a condition is called cyanosis. That is why in Delaney it had the appearance of cyanogen poisoning. The effect was the same. But the trace of cyanogen in the air was merely a coincidence, Haynes. It wasn't cyanogen that killed. But it was something quite as deadly—and far harder to trace—a new germ!"
We listened, fascinated.