"Will work," Macklin said thoughtfully. "The operative word. It hasn't worked then?"
"Certainly it has," Ferris said. "On rats, on chimps...."
"But not on humans?" Macklin asked.
"Not yet," Mitchell admitted.
"Well," Macklin said. "Well." He thumped pipe ashes out into his palm. "Certainly you can get volunteers. Convicts. Conscientious objectors from the Army."
"We want you," Ferris told him.
Macklin coughed. "I don't want to overestimate my value but the government wouldn't like it very well if I died in the middle of this project. My wife would like it even less."
Ferris turned his back on the mathematician. Mitchell could see him mouthing the word yellow.
"Doctor," Mitchell said quickly, "I know it's a tremendous favor to ask of a man of your position. But you can understand our problem. Unless we can produce quick, conclusive and dramatic proof of our studies we can get no more financial backing. We should run a large-scale field test. But we haven't the time or money for that. We can cure the headaches of one person and that's the limit of our resources."
"I'm tempted," Macklin said hesitantly, "but the answer is go. I mean 'no'. I'd like to help you out, but I'm afraid I owe too much to others to take the rest—the risk, I mean."