ANR | Edison, Clarence Dally, and the Hidden Perils of the X-Rays: Edison Fears the Rays.
"Don't talk to me about X-rays," he said. "I am afraid of them. I stopped experimenting with them two years ago, when I came near to losing my eyesight and Dally, my assistant practically lost the use of both of his arms. I am afraid of radium and polonium too, and I don't want to monkey with them.