This meant that the chances of an organism from outer space being suited to harm man were very slim. Everyone recognized this, but felt that Wildfire had to be constructed in any event. Burton certainly agreed, but felt in an odd way that his prophecy had come true.

Clearly, the bug they had found could kill men. But it was not really adapted to men, because it killed and died within the organism. It could not be transmitted from corpse to corpse. It existed for a second or two in its host, and then died with it.

Satisfying intellectually, he thought.

But practically speaking they still had to isolate it, understand it, and find a cure.

Burton already knew something about transmission, and something about the mechanism of death: clotting of the blood. The question remained—How did the organisms get into the body?

Because transmission appeared to be airborne, contact with skin and lungs seemed likely. Possibly the organisms burrowed right through the skin surface. Or they might be inhaled. Or both.

How to determine it?

He considered putting protective suitings around an experimental animal to cover all but the mouth. That was possible, but it would take a long time. He sat and worried about the problem for an hour.

Then he hit upon a more likely approach.

He knew that the organism killed by clotting blood. Very likely it would initiate clotting at the point of entrance into the body. If skin, clotting would start near the surface. If lungs, it would begin in the chest, radiating outward.

This was something he could test. By using radioactively tagged blood proteins, and then following his animals with scintillometer scans, he could determine where in the body the blood first clotted.

He prepared a suitable animal, choosing a rhesus monkey because its anatomy was more human than a rat's. He infused the radioactive tagging substance, a magnesium isotope, into the monkey and calibrated the scanner. After allowing equilibration, he tied the monkey down and positioned the scanner overhead.

He was now ready to begin.

The scanner would print out its results on a series of human block outlines. He set the computer printing program and then exposed the rhesus to air containing the lethal microorganism.

Immediately, the printout began to clatter out from the computer:

It was all over in three seconds. The graphic printout told him what he needed to know, that clotting began in the lungs and spread outward through the rest of the body.

But there was an additional piece of information gained. Burton later said, "I had been concerned that perhaps death and clotting did not coincide—or at least did not coincide exactly. It seemed impossible to me that death could occur in three seconds, but it seemed even more unlikely that the total blood volume of the body-five quarts-could solidify in so short a period. I was curious to know whether a single crucial clot might form, in the brain, perhaps, and the rest of the body clot at a slower pace."