In 1944, 26-year-old Marshall Sutton was a young idealist who wanted to change the world for the better. As a conscientious objector and Quaker, he refused to fight in the war but he still craved the chance to help his country.

"I wanted to identify with the suffering in the world at that time," he says. "I wanted to do something for society. I wanted to put myself in a little danger."

That danger came, unexpectedly, in the shape of a small brochure with a picture of children on the front.

"Will you starve that they be better fed?" it asked. It was a call for volunteers to act as human guinea pigs in a medical experiment at the University of Minnesota.