For nearly a decade, Ketchum, a psychiatrist, went about his work in the belief that chemicals are more humane instruments of warfare than bullets and shrapnel—or, at least, he told himself such things. To achieve his dream, he worked tirelessly at a secluded Army research facility, testing chemical weapons on hundreds of healthy soldiers, and thinking all along that he was doing good.

http://www.newyorker.com/magazine/2012/12/17/operation-delir...